When i build the VR One demo scene in Unity 5.1.2f to my Galaxy S5 i get the artifacts you can see on the images below:
The first image shows the artifacts i get when i just start the app in landscape mode and force it to stay in landscape. If i allow rotation to portrait i get something like on the second image in portrait and it gets even worse when rotating back (Cant post three links...).
When i turn off the distortion everything is fine but thats not an option for the final app.
I also modified the shader to give out only solid colors and even if i just write out solid green, i get the black artifacts.
I created an empty project and imported the package you can download here. I already get the artifacts without changing anything.
Any ideas what could cause this? My guess would be some memory problem...